The present invention relates to routing and congestion control in packet switching networks. More specifically, but without limitation thereto, the present invention relates to a method for estimating the cell loss rate of a finite buffer asynchronous transfer mode multiplexer.
Asynchronous transfer mode (ATM) networks are well suited to global telecommunications because of their ability to support high speed multimedia applications. However, many important problems related to the design of an ATM network remain unresolved, such as buffer dimensioning, congestion control, and message routing. Message routing in an ATM network poses challenges and difficulties that are quite different from those of current packet-switched networks. Unlike packet-switched networks that offer no performance guarantees to their clients, an ATM network must select routes that satisfy the performance requirements of all the clients admitted to the network. Congestion may be avoided simply by admitting very few clients, however this approach does not make efficient use of network resources. Efficient utilization of network resources results when as many clients as possible are admitted, but network performance for each client may be degraded. The difficulty in achieving successful routing in an ATM network lies in the lack of a method for quantifying the degree of performance degradation when the individual channels comprising the network current are shared by many clients. In an ATM network, message traffic is formatted and transmitted in units of small, fixed-length packets called cells. Cell loss, along with cell delay and delay variation, are key performance criteria.
A need thus continues for a method of estimating cell loss rate for an asynchronous transfer mode statistical multiplexer.